xref: /freebsd/sys/dev/vt/vt_font.c (revision a0409676120c1e558d0ade943019934e0f15118d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2009 The FreeBSD Foundation
5  * All rights reserved.
6  *
7  * This software was developed by Ed Schouten under sponsorship from the
8  * FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/refcount.h>
39 #include <sys/systm.h>
40 
41 #include <dev/vt/vt.h>
42 
43 static MALLOC_DEFINE(M_VTFONT, "vtfont", "vt font");
44 
45 /* Some limits to prevent abnormal fonts from being loaded. */
46 #define	VTFONT_MAXMAPPINGS	65536
47 #define	VTFONT_MAXGLYPHS	131072
48 #define	VTFONT_MAXGLYPHSIZE	2097152
49 #define	VTFONT_MAXDIMENSION	128
50 
51 static uint16_t
52 vtfont_bisearch(const vfnt_map_t *map, unsigned int len, uint32_t src)
53 {
54 	int min, mid, max;
55 
56 	min = 0;
57 	max = len - 1;
58 
59 	/* Empty font map. */
60 	if (len == 0)
61 		return (0);
62 	/* Character below minimal entry. */
63 	if (src < map[0].vfm_src)
64 		return (0);
65 	/* Optimization: ASCII characters occur very often. */
66 	if (src <= map[0].vfm_src + map[0].vfm_len)
67 		return (src - map[0].vfm_src + map[0].vfm_dst);
68 	/* Character above maximum entry. */
69 	if (src > map[max].vfm_src + map[max].vfm_len)
70 		return (0);
71 
72 	/* Binary search. */
73 	while (max >= min) {
74 		mid = (min + max) / 2;
75 		if (src < map[mid].vfm_src)
76 			max = mid - 1;
77 		else if (src > map[mid].vfm_src + map[mid].vfm_len)
78 			min = mid + 1;
79 		else
80 			return (src - map[mid].vfm_src + map[mid].vfm_dst);
81 	}
82 
83 	return (0);
84 }
85 
86 const uint8_t *
87 vtfont_lookup(const struct vt_font *vf, term_char_t c)
88 {
89 	uint32_t src;
90 	uint16_t dst;
91 	size_t stride;
92 	unsigned int normal_map;
93 	unsigned int bold_map;
94 
95 	src = TCHAR_CHARACTER(c);
96 	if (TCHAR_FORMAT(c) & TF_CJK_RIGHT) {
97 		normal_map = VFNT_MAP_NORMAL_RIGHT;
98 		bold_map = VFNT_MAP_BOLD_RIGHT;
99 	} else {
100 		normal_map = VFNT_MAP_NORMAL;
101 		bold_map = VFNT_MAP_BOLD;
102 	}
103 
104 	if (TCHAR_FORMAT(c) & TF_BOLD) {
105 		dst = vtfont_bisearch(vf->vf_map[bold_map],
106 		    vf->vf_map_count[bold_map], src);
107 		if (dst != 0)
108 			goto found;
109 	}
110 	dst = vtfont_bisearch(vf->vf_map[normal_map],
111 	    vf->vf_map_count[normal_map], src);
112 
113 found:
114 	stride = howmany(vf->vf_width, 8) * vf->vf_height;
115 	return (&vf->vf_bytes[dst * stride]);
116 }
117 
118 struct vt_font *
119 vtfont_ref(struct vt_font *vf)
120 {
121 
122 	refcount_acquire(&vf->vf_refcount);
123 	return (vf);
124 }
125 
126 void
127 vtfont_unref(struct vt_font *vf)
128 {
129 	unsigned int i;
130 
131 	if (refcount_release(&vf->vf_refcount)) {
132 		for (i = 0; i < VFNT_MAPS; i++)
133 			free(vf->vf_map[i], M_VTFONT);
134 		free(vf->vf_bytes, M_VTFONT);
135 		free(vf, M_VTFONT);
136 	}
137 }
138 
139 static int
140 vtfont_validate_map(vfnt_map_t *vfm, unsigned int length,
141     unsigned int glyph_count)
142 {
143 	unsigned int i, last = 0;
144 
145 	for (i = 0; i < length; i++) {
146 		/* Not ordered. */
147 		if (i > 0 && vfm[i].vfm_src <= last)
148 			return (EINVAL);
149 		/*
150 		 * Destination extends amount of glyphs.
151 		 */
152 		if (vfm[i].vfm_dst >= glyph_count ||
153 		    vfm[i].vfm_dst + vfm[i].vfm_len >= glyph_count)
154 			return (EINVAL);
155 		last = vfm[i].vfm_src + vfm[i].vfm_len;
156 	}
157 
158 	return (0);
159 }
160 
161 int
162 vtfont_load(vfnt_t *f, struct vt_font **ret)
163 {
164 	size_t glyphsize, mapsize;
165 	struct vt_font *vf;
166 	int error;
167 	unsigned int i;
168 
169 	/* Make sure the dimensions are valid. */
170 	if (f->width < 1 || f->height < 1)
171 		return (EINVAL);
172 	if (f->width > VTFONT_MAXDIMENSION || f->height > VTFONT_MAXDIMENSION ||
173 	    f->glyph_count > VTFONT_MAXGLYPHS)
174 		return (E2BIG);
175 
176 	/* Not too many mappings. */
177 	for (i = 0; i < VFNT_MAPS; i++)
178 		if (f->map_count[i] > VTFONT_MAXMAPPINGS)
179 			return (E2BIG);
180 
181 	/* Character 0 must always be present. */
182 	if (f->glyph_count < 1)
183 		return (EINVAL);
184 
185 	glyphsize = howmany(f->width, 8) * f->height * f->glyph_count;
186 	if (glyphsize > VTFONT_MAXGLYPHSIZE)
187 		return (E2BIG);
188 
189 	/* Allocate new font structure. */
190 	vf = malloc(sizeof *vf, M_VTFONT, M_WAITOK | M_ZERO);
191 	vf->vf_bytes = malloc(glyphsize, M_VTFONT, M_WAITOK);
192 	vf->vf_height = f->height;
193 	vf->vf_width = f->width;
194 	vf->vf_refcount = 1;
195 
196 	/* Allocate, copy in, and validate mappings. */
197 	for (i = 0; i < VFNT_MAPS; i++) {
198 		vf->vf_map_count[i] = f->map_count[i];
199 		if (f->map_count[i] == 0)
200 			continue;
201 		mapsize = f->map_count[i] * sizeof(vfnt_map_t);
202 		vf->vf_map[i] = malloc(mapsize, M_VTFONT, M_WAITOK);
203 		error = copyin(f->map[i], vf->vf_map[i], mapsize);
204 		if (error)
205 			goto bad;
206 		error = vtfont_validate_map(vf->vf_map[i], vf->vf_map_count[i],
207 		    f->glyph_count);
208 		if (error)
209 			goto bad;
210 	}
211 
212 	/* Copy in glyph data. */
213 	error = copyin(f->glyphs, vf->vf_bytes, glyphsize);
214 	if (error)
215 		goto bad;
216 
217 	/* Success. */
218 	*ret = vf;
219 	return (0);
220 
221 bad:	vtfont_unref(vf);
222 	return (error);
223 }
224